THE IMPACT OF USE DIFFERENT TYPE OF IMAGE INTERPOLATION METHODS ON THE ACCURACY OF THE RECONSTRUCTION OF SKULL ANATOMICAL MODEL

2020 ◽  
Vol 32 (01) ◽  
pp. 2050008
Author(s):  
Grzegorz Budzik ◽  
Paweł Turek
Keyword(s):  
Gold Standard ◽  
Nasal Bone ◽  
Region Growing ◽  
Volume Effect ◽  
Partial Volume Effect ◽  
Bone Area ◽  
Statistical Parameters ◽  
Data Editing ◽  
Craniofacial Tissue ◽  
The Impact

The paper presents comparative studies concerning the use different methods of image resampling on the accuracy of the reconstruction of oral and maxillofacial geometry. The study was conducted on 14 different patients. In order to extract the oral and maxillofacial models from DICOM data, a region-growing algorithm was used. Thresholds were set above 200 HU to select only craniofacial tissue. After an oral and maxillofacial tissue was segmented from DICOM data, a marching cubes algorithm was used for computing isosurfaces. Model with [Formula: see text][Formula: see text]mm voxel was chosen as the gold standard for models of [Formula: see text][Formula: see text]mm structure and improved with image resampling filters. In the study 7 different kernels were used allowing for filtration. The image resampling filters minimize maximum positive deviations, especially in the occipital, mandible and zygomatic bone area, and maximum negative deviations in the area of the maxilla and nasal bone. Lanczos filtering is the best method of interpolation as compared to other used methods, due to significantly increased visibility of the edges of the segmented structures. As a result of applying this method, partial volume effect artifact was minimized. The distributions and statistical parameters of resampled DICOM data prove that on this stage of data editing, it is possible to increase the accuracy of segmentation and reconstruction of the geometry.

scholarly journals Impact of Different Analytic Approaches on the Analysis of the Breast Fibroglandular Tissue Using Diffusion Weighted Imaging

2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Yoon Jung Choi ◽  
Jeon-Hor Chen ◽  
Hon J. Yu ◽  
Yifan Li ◽  
Min-Ying Su
Keyword(s):  
Region Of Interest ◽  
Volume Effect ◽  
Partial Volume Effect ◽  
Normal Breast ◽  
Unilateral Breast Cancer ◽  
Partial Volume ◽  
Apparent Diffusion ◽  
Adc Values ◽  
Highly Correlated ◽  
The Impact

Purpose. This study investigated the impact of the different region of interest (ROI) approaches on measurement of apparent diffusion coefficient (ADC) values in the breast firbroglandular tissue (FT). Methods. Breast MR images of 38 women diagnosed with unilateral breast cancer were studied. Percent density (PD) and ADC were measured from the contralateral normal breast. Four different ROIs were used for ADC measurement. The measured PD and ADC were correlated. Results. Among the four ROIs, the manually placed small ROI on FT gave the highest mean ADC (ADC = 1839 ± 343 [×10−6 mm2/s]), while measurement from the whole breast gave the lowest mean ADC (ADC = 933 ± 383 [×10−6 mm2/s]). The ADC measured from the whole breast was highly correlated with PD with r=0.95. In slice-to-slice comparison, the central slices with more FT had higher ADC values than the peripheral slices did, presumably due to less partial volume effect from fat. Conclusions. Our results indicated that the measured ADC heavily depends on the composition of breast tissue contained in the ROI used for the ADC measurements. Women with low breast density showing lower ADC values were most likely due to the partial volume effect of fatty tissues.

scholarly journals Development of an Electronic Algorithm to Identify Inappropriate Antibiotic Prescribing for Pediatric Pharyngitis

2020 ◽  
Vol 41 (S1) ◽  
pp. s188-s189
Author(s):  
Jeffrey Gerber ◽  
Robert Grundmeier ◽  
Keith Hamilton ◽  
Lauri Hicks ◽  
Melinda Neuhauser ◽  
...  
Keyword(s):  
Predictive Value ◽  
Gold Standard ◽  
Antibiotic Stewardship ◽  
Chart Review ◽  
Antibiotic Use ◽  
Audit And Feedback ◽  
Urgent Care ◽  
Antibiotic Prescribing ◽  
Tract Infections ◽  
The Impact

Background: Antibiotic overuse contributes to antibiotic resistance and unnecessary adverse drug effects. Antibiotic stewardship interventions have primarily focused on acute-care settings. Most antibiotic use, however, occurs in outpatients with acute respiratory tract infections such as pharyngitis. The electronic health record (EHR) might provide an effective and efficient tool for outpatient antibiotic stewardship. We aimed to develop and validate an electronic algorithm to identify inappropriate antibiotic use for pediatric outpatients with pharyngitis. Methods: This study was conducted within the Children’s Hospital of Philadelphia (CHOP) Care Network, including 31 pediatric primary care practices and 3 urgent care centers with a shared EHR serving >250,000 children. We used International Classification of Diseases, Tenth Revision (ICD-10) codes to identify encounters for pharyngitis at any CHOP practice from March 15, 2017, to March 14, 2018, excluding those with concurrent infections (eg, otitis media, sinusitis), immunocompromising conditions, or other comorbidities that might influence the need for antibiotics. We randomly selected 450 features for detailed chart abstraction assessing patient demographics as well as practice and prescriber characteristics. Appropriateness of antibiotic use based on chart review served as the gold standard for evaluating the electronic algorithm. Criteria for appropriate use included streptococcal testing, use of penicillin or amoxicillin (absent β-lactam allergy), and a 10-day duration of therapy. Results: In 450 patients, the median age was 8.4 years (IQR, 5.5–9.0) and 54% were women. On chart review, 149 patients (33%) received an antibiotic, of whom 126 had a positive rapid strep result. Thus, based on chart review, 23 subjects (5%) diagnosed with pharyngitis received antibiotics inappropriately. Amoxicillin or penicillin was prescribed for 100 of the 126 children (79%) with a positive rapid strep test. Of the 126 children with a positive test, 114 (90%) received the correct antibiotic: amoxicillin, penicillin, or an appropriate alternative antibiotic due to b-lactam allergy. Duration of treatment was correct for all 126 children. Using the electronic algorithm, the proportion of inappropriate prescribing was 28 of 450 (6%). The test characteristics of the electronic algorithm (compared to gold standard chart review) for identification of inappropriate antibiotic prescribing were sensitivity (99%, 422 of 427); specificity (100%, 23 of 23); positive predictive value (82%, 23 of 28); and negative predictive value (100%, 422 of 422). Conclusions: For children with pharyngitis, an electronic algorithm for identification of inappropriate antibiotic prescribing is highly accurate. Future work should validate this approach in other settings and develop and evaluate the impact of an audit and feedback intervention based on this tool.Funding: NoneDisclosures: None

scholarly journals Development of an Electronic Algorithm to Target Outpatient Antimicrobial Stewardship Efforts for Acute Bronchitis

2020 ◽  
Vol 41 (S1) ◽  
pp. s32-s32
Author(s):  
Ebbing Lautenbach ◽  
Keith Hamilton ◽  
Robert Grundmeier ◽  
Melinda Neuhauser ◽  
Lauri Hicks ◽  
...  
Keyword(s):  
Antimicrobial Stewardship ◽  
Predictive Value ◽  
Gold Standard ◽  
Chart Review ◽  
Acute Bronchitis ◽  
Antibiotic Use ◽  
Antibiotic Prescribing ◽  
Diagnostic Codes ◽  
Icd 10 ◽  
The Impact

Background: Antibiotic resistance has increased at alarming rates, driven predominantly by antibiotic overuse. Although most antibiotic use occurs in outpatients, antimicrobial stewardship programs have primarily focused on inpatient settings. A major challenge for outpatient stewardship is the lack of accurate and accessible electronic data to target interventions. We sought to develop and validate an electronic algorithm to identify inappropriate antibiotic use for outpatients with acute bronchitis. Methods: This study was conducted within the University of Pennsylvania Health System (UPHS). We used ICD-10 diagnostic codes to identify encounters for acute bronchitis at any outpatient UPHS practice between March 15, 2017, and March 14, 2018. Exclusion criteria included underlying immunocompromising condition, other comorbidity influencing the need for antibiotics (eg, emphysema), or ICD-10 code at the same visit for a concurrent infection (eg, sinusitis). We randomly selected 300 (150 from academic practices and 150 from nonacademic practices) eligible subjects for detailed chart abstraction that assessed patient demographics and practice and prescriber characteristics. Appropriateness of antibiotic use based on chart review served as the gold standard for assessment of the electronic algorithm. Because antibiotic use is not indicated for this study population, appropriateness was assessed based upon whether an antibiotic was prescribed or not. Results: Of 300 subjects, median age was 61 years (interquartile range, 50–68), 62% were women, 74% were seen in internal medicine (vs family medicine) practices, and 75% were seen by a physician (vs an advanced practice provider). On chart review, 167 (56%) subjects received an antibiotic. Of these subjects, 1 had documented concern for pertussis and 4 had excluding conditions for which there were no ICD-10 codes. One received an antibiotic prescription for a planned dental procedure. Thus, based on chart review, 161 (54%) subjects received antibiotics inappropriately. Using the electronic algorithm based on diagnostic codes, underlying and concurrent conditions, and prescribing data, the number of subjects with inappropriate prescribing was 170 (56%) because 3 subjects had antibiotic prescribing not noted based on chart review. The test characteristics of the electronic algorithm (compared to gold standard chart review) for identification of inappropriate antibiotic prescribing were the following: sensitivity, 100% (161 of 161); specificity, 94% (130 of 139); positive predictive value, 95% (161 of 170); and negative predictive value, 100% (130 of 130). Conclusions: For outpatients with acute bronchitis, an electronic algorithm for identification of inappropriate antibiotic prescribing is highly accurate. This algorithm could be used to efficiently assess prescribing among practices and individual clinicians. The impact of interventions based on this algorithm should be tested in future studies.Funding: NoneDisclosures: None

Partial volume effect of SPECT images in PRRT with 177Lu labelled somatostatin analogues: A practical solution

2019 ◽  
Vol 57 ◽  
pp. 153-159 ◽  
Author(s):  
Domenico Finocchiaro ◽  
Salvatore Berenato ◽  
Elisa Grassi ◽  
Valentina Bertolini ◽  
Gastone Castellani ◽  
...  
Keyword(s):  
Somatostatin Analogues ◽  
Volume Effect ◽  
Partial Volume Effect ◽  
Practical Solution ◽  
Partial Volume ◽  
Spect Images

Spectrum separation resolves partial-volume effect of MRSI as demonstrated on brain tumor scans

2008 ◽  
Vol 21 (10) ◽  
pp. 1030-1042 ◽  
Author(s):  
Yuzhuo Su ◽  
Sunitha B. Thakur ◽  
Karimi Sasan ◽  
Shuyan Du ◽  
Paul Sajda ◽  
...  
Keyword(s):  
Brain Tumor ◽  
Volume Effect ◽  
Partial Volume Effect ◽  
Partial Volume

Segmentation of the skull in MRI volumes using a deformable model and taking the partial volume effect into account

1999 ◽  
Author(s):  
Hilmi Rifai ◽  
Isabelle Bloch ◽  
Seth A. Hutchinson ◽  
Joe Wiart ◽  
Line Garnero
Keyword(s):  
Volume Effect ◽  
Partial Volume Effect ◽  
Deformable Model ◽  
Partial Volume

scholarly journals Ventricle Boundary in CT: Partial Volume Effect and Local Thresholds

2010 ◽  
Vol 2010 ◽  
pp. 1-6 ◽  
Author(s):  
Ihar Volkau ◽  
Fiftarina Puspitasari ◽  
Wieslaw L. Nowinski
Keyword(s):  
Computed Tomography ◽  
Cerebrospinal Fluid ◽  
Grey Matter ◽  
Ground Truth ◽  
Gaussian Mixture ◽  
Volume Effect ◽  
Partial Volume Effect ◽  
Partial Volume ◽  
Image Histogram ◽  
Global Threshold

We present a mathematical frame to carry out segmentation of cerebrospinal fluid (CSF) of ventricular region in computed tomography (CT) images in the presence of partial volume effect (PVE). First, the image histogram is fitted using the Gaussian mixture model (GMM). Analyzing the GMM, we find global threshold based on parameters of distributions for CSF, and for the combined white and grey matter (WGM). The parameters of distribution of PVE pixels on the boundary of ventricles are estimated by using a convolution operator. These parameters are used to calculate local thresholds for boundary pixels by the analysis of contribution of the neighbor pixels intensities into a PVE pixel. The method works even in the case of an almost unimodal histogram; it can be useful to analyze the parameters of PVE in the ground truth provided by the expert.

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